1. Field of the Invention
This invention relates to a linear drive mechanism for accurately driving a driven member, such as a holder for the operating head of a laser processing system, in a given linear direction, characterized by the use of motor-driven cable means for connecting the driven member relative to a housing within which it is slidably mounted.
2. Brief Description of the Prior Art
Various types of linear drive mechanisms have been proposed in the prior art for converting rotary motion of an object--such as the output shaft of an electric hydraulic or pneumatic motor--to linear motion for driving a member in a given linear direction. Previously it has been proposed to use threaded spindles or pinion-gear and rack arrangements to effect the desired rotary to linear conversion, which arrangements possess the drawback of having moving parts that move against one another, thereby resulting in undesirable wear of the components. Furthermore, manufacturing tolerances must be taken into account, thereby affecting the accuracy of the linear displacement of the driven member.
It has been proposed in the patented prior art to utilize flexible cables or bands for connecting a rotary driving member with a linearly displaceable driven member, as shown, for example, by the Hasler U.S. Pat. No. 4,366,722, the Blount British patent No. 2,088,987, the Kolb German Off. No. 2,431,881, and the Jakob European application No. 672,844.
The present invention was developed to provide an improved linear drive mechanism that is particularly suitable for accurately driving a driven member--such as the holder for the connection head of a laser processing system--in a linear direction relative to a housing within which it is mounted.